Dental imaging device

ABSTRACT

A method to acquire dental images of a patient with a support defining a chamber that is in communication with an outside of said chamber via a first opening and via a second opening. The method includes the following steps: fixing a mobile phone in front of the second opening; positioning the first opening in front of a mouth of the patient; and acquiring at least one dental image by means of the mobile phone.

TECHNICAL FIELD

The present invention relates to a dental imaging device, in particularfor implementing a method such as described in international applicationPCT/EP2015/074896.

PRIOR ART

PCT/EP2015/074896 describes a method allowing, on the basis of

-   -   a three-dimensional model of the teeth of a patient produced        before treatment, referred to as the “initial reference model”;        then    -   a simple “updated” image of the teeth taken during treatment,        for example a photograph taken by the patient,

the positioning of the teeth at the moment of acquisition of the updatedimage to be accurately evaluated.

This method consists in an iterative process in which, upon eachiteration, models of teeth from the initial reference model are moved,then optimum conditions for observing the initial model thus modified(referred to as the “test reference model”) are determined, the optimumobservation conditions being defined as the conditions allowing the testreference model to be observed so that the view of said model is asclose as possible to the updated image. A succession of “test referencemodels” are tested until obtaining a maximum level of correspondencebetween a test reference model and the updated image. This last testreference model is then considered to be representative of the teeth intheir position at the moment of acquisition of the updated image.Ideally, this model, referred to as the “updated reference model”, is adigital three-dimensional reference model from which the updated imagecould have been taken had this model been real. In practice, it actuallyrepresents, with a high level of accuracy, the teeth in their positionat the moment of acquisition of the updated image.

Generally, multiple updated images are required to evaluate thepositioning of multiple teeth. The method must be implemented for eachupdated image. The method described in international applicationPCT/EP2015/074896 may therefore be lengthy in its implementation.

Furthermore, the updated images may be used to detect variations in theappearance of the teeth or of the soft tissues such as the gums, and inparticular in their color and in their translucence. Comparing variousphotos does not however always yield satisfactory results.

One object of the present invention is to provide an at least partialresponse to these problems.

SUMMARY OF THE INVENTION

The invention provides an imaging device including:

-   -   a support;    -   a dental retractor, fastened to the support, defining a        retractor opening; and    -   means for fastening an image acquisition apparatus to the        support in a position in which the acquisition apparatus is        oriented so as to receive an image of the retractor opening.

As will become more clearly apparent throughout the rest of thedescription, a device according to the invention advantageously makes itpossible to define a precise positioning of the image acquisitionapparatus with respect to the dental retractor. In particular, thedistance between the means for fastening the image acquisition apparatusand the dental retractor may be predetermined, thereby allowing theadjustment of the image acquisition apparatus to be accelerated.Furthermore, the orientation of the image acquisition apparatus withrespect to the support may be predetermined, thereby making it possibleto approximately predict the representation of the dental retractor,and, through the dental retractor, of the arches of the patient, on theupdated images acquired by means of the image acquisition apparatus. Thelater processing of the images, in particular according to the method ofPCT/EP/2015/074896, is accelerated thereby.

According to a first main refinement, the device includes a mirrorfastened to the support and said fastening means are configured tofasten the image acquisition apparatus to the support in a position inwhich the acquisition apparatus is oriented so as to receive a compositeimage including a direct image of the retractor opening and an image ofthe retractor opening reflected by the mirror.

In a service position in which the dental retractor is positioned on themouth of the patient and the image acquisition apparatus is fastened tothe support by said fastening means, said acquisition apparatus thussees a composite image including a direct image of the teeth that isobserved directly through the retractor opening and a reflected image ofthe teeth returned by the mirror.

As will become more clearly apparent later on in the description, adevice according to the first main refinement of the invention thusallows multiple images of the teeth, observed from different angles, tobe acquired simultaneously. The acquisition process is accelerated as aresult.

In addition, determining the conditions for acquiring the direct image,or the reflected image, makes it possible to determine the conditionsfor acquiring the reflected image, or the direct image, respectively. Itis in fact sufficient to have knowledge of the orientation of the mirrorand its position with respect to the dental retractor and to theacquisition apparatus in order to determine the positioning in space ofthe acquisition apparatus which would have allowed, in the absence ofthe mirror, the reflected image to be observed. The implementation of amethod such as that in international application PCT/EP2015/074896 isconsequently considerably accelerated as a result.

Specifically, typically, the patient takes a photo of his or her teethfrom the right, a photo of his or her teeth from the left and a photo ofhis or her teeth from the front. However, the software implementing themethod described in international application PCT/EP2015/074896 ignoresthe position of the acquisition apparatus in these various steps and isnot able to deduce it by processing the other images. It must thereforefind it again each time in order to define the optimum observationconditions.

According to a second main refinement, the device includes

-   -   a colorimetric calibration chart and/or a translucence        calibration chart, preferably both a colorimetric calibration        chart and a translucence calibration chart, preferably fastened        to the support; and    -   preferably a light source that is oriented so as to illuminate        both the teeth of the patient through the retractor opening and        said colorimetric calibration chart and/or said translucence        calibration chart, said fastening means of the acquisition        apparatus being configured to immobilize the acquisition        apparatus in a position in which it is oriented so as to receive        an image of both the retractor opening and of said colorimetric        calibration chart and/or of said translucence calibration chart.

As will become more clearly apparent later on in the description, adevice according to the second main refinement of the invention thusallows the color and the translucence of the teeth and/or of the softtissues, such as the gums, to be accurately determined. In particular,the illumination may be monitored so as to limit disruptions due to thelighting environment of the device. Various images taken at differenttimes may therefore be accurately compared.

According to a third main refinement, the support takes the form of abox so as to define a chamber that is in communication with the outsidesubstantially only via the retractor opening and via an acquisitionopening through which the acquisition apparatus fastened to the supportreceives at least one image of the retractor opening.

Thus, the support defines a closed chamber when the opening of thedental retractor and the acquisition opening are obturated.

Advantageously, the inside of the chamber therefore receivessubstantially no luminous radiation from the outside, therebyfacilitating the control of the illumination during the acquisition ofupdated images. A closed box also protects the patient's privacy.

In one embodiment, the dental retractor is mounted mobile, movablymounted, on the support, preferably rotatably mounted on the support,preferably around a single axis, preferably an horizontal axis in theservice position, so that a gap between the support and the dentalretractor occurs when the dental retractor is moved relative to thesupport. An obturator is provided to extended so as to obturate thisgap. In particular, the obturator may have the shape of a flexiblemembrane, the edge of which is rigidly fixed on the dental retractor andon the support. Such a membrane may be elastic.

Advantageously, the flexibility and/or the elasticity of the membraneallows the membrane to obturate the gap between the support and thedental retractor, even if the dimensions of this gaps varies when thedental retractor is moved relative to the support.

Improvements

According to a first improvement, the imaging device has a support whichcomprises a rigid portion on which the acquisition apparatus is to befastened to, and a deformable portion defining a retractor opening,preferably extending between the rigid portion and a conventional dentalretractor.

The deformability of the deformable portion defining a retractor openingallows an adaptation of the imaging device to the patient. Consequently,the same support and dental retractor may be used for patients havingdifferent anatomies. Using the device is made more comfortable and thequality of the acquired images is improved.

The support is preferably in the form of a box, and has a lateral walldefining a chamber in communication with the outside via a retractoropening and an acquisition opening through which the acquisitionapparatus fastened to the support receives at least one image of theretractor opening. The deformable portion is preferably at least aportion of the lateral wall of the support.

In an embodiment, the deformable portion enables limited movements ofthe rigid portion relative to the retractor opening, in particular sothat the variation of the angle between the optical axis of the imageacquisition apparatus and the retractor opening be limited to less than30°, less than 20°, less than 10°, or less than 5°. This variation ispreferably greater that 1° or 3°.

The rigid portion, preferably having a tubular shape, makes thefastening of the image acquisition apparatus easier. Preferably, itslength is greater than 5 cm, and less than 20 cm, so that the patientmay easily grab it to hold the support.

The deformable portion preferably allows an extension and/or acollapsing of the support.

Preferably, the deformable portion may be inserted, at least partly,into the rigid portion and extracted from said rigid portion. Theimaging device may thereby be compacted.

In an embodiment, the deformable portion may be detached of the rigidportion. This advantageously makes shipment easier.

According to a second improvement, the support is extendable from acollapsed configuration to a fully extended configuration, and/orcollapsible from said fully extended configuration to said collapsedconfiguration.

Put differently, at least one dimension of the support has a “collapsed”value D_(c) in a collapsed configuration, and an “extended” value D_(e),greater than the collapsed value D_(c), in the fully extendedconfiguration.

In a preferred embodiment, the support, preferably in the form of a box,has a lateral wall defining a chamber in communication with the outsidevia a retractor opening and an acquisition opening through which theacquisition apparatus fastened to the support receives at least oneimage of the retractor opening, said lateral wall being extendableand/or collapsible between a fully extended configuration and acollapsed configuration.

Said dimension is preferably an overall dimension of the chamber,preferably its length, and the ratio D_(c)/D_(e) is preferably less than0.5.

Advantageously, the bulk of the support is reduced in the collapsedconfiguration, so that storage and shipment costs are reduced.

Preferably, the support is configured so that, in the fully extendedconfiguration and/or in an intermediate configuration between thecollapsed and fully extended configurations, the angulation between anoptical axis of the image acquisition apparatus and the retractoropening and/or the distance between the image acquisition apparatus andthe retractor opening is (are) different than in the collapsedconfiguration.

Advantageously, the extension of the support therefore enables amodification of the acquisition conditions.

Preferably, the lateral wall is foldable. In particular, the lateralwall preferably comprises a bellow.

Preferably, the support is configured so that extension and/orcollapsing of the support is fully or partly guided.

“Fully guidance” or “hard guidance” means that there is only one path ofintermediate configurations between the collapsed configuration and aunique fully extended configuration.

“Partial guidance”, or “soft guidance” means that several paths arepossible between the collapsed configuration and a unique fully extendedconfiguration or several fully extended configurations, each pathenabling different deformations but some of these deformations requiringmore efforts than other. The guidance is not hard since the patient hasseveral possibilities to deform the support. However, the patient canfeel that said deformations are not recommended.

Advantageously, the patient can therefore feel one or several privilegedconfigurations from which greater efforts are necessary to go away.

The privileged configurations preferably correspond to predeterminedacquisition conditions to acquire images according to predeterminedangulations and/or distances.

For instance, after having fastened a mobile phone on the support, andhaving inserted the dental retractor into his mouth, the patientmanipulates the mobile phone. When he pushes it to his right, he feels afirst “angle” resistance when the optical axis of the mobile phone makesan angle of about 40° with the plane of the retractor opening. Thisinforms the patient that this angle is appropriate to acquire an image.

When he pushes the mobile phone toward the retractor opening, he feels afirst “distance” resistance when the distance between the mobile phoneand the retractor opening is about 20 cm. This informs the patient thatthis distance is appropriate to acquire a first image.

The patient has then reached a first privileged configuration.

The patient may further push the mobile phone to his right and/or towardthe retractor opening, by increasing the pushing force against saidfirst resistances. Once he has left the first privileged configuration,the “angle” and “distance” resistances decrease. When the patientfurther pushes the mobile phone to his right, he may feel a second“angle” resistance when the optical axis of the mobile phone makes anangle of about 60° with the plane of the retractor opening. This informsthe patient that this angle is appropriate to acquire an image. When hefurther pushes the mobile phone toward the retractor opening, he mayfeel a second “distance” resistance when the distance between the mobilephone and the retractor opening is about 10 cm. This informs the patientthat this distance is appropriate to acquire a second image.

The patient has then reached a second privileged configuration.

According to a third improvement, at least a portion of the support isdegradable by composting and/or biodegradation, preferably according tothe European standard EN 13432, preferably with a residue of less than10%, preferably less than 5%, preferably less 1% in 6 months.

Said portion is preferably made in a fibrous cellulosic material,preferably in cardboard.

Preferably, more than 50%, 70%, 80%, or 90% of the support, inpercentage by weight, is so degradable.

In a preferred embodiment, the support, preferably in the form of a box,has a lateral wall defining a chamber in communication with the outsidevia a retractor opening and an acquisition opening through which theacquisition apparatus fastened to the support receives at least oneimage of the retractor opening, said degradable portion including orbeing said lateral wall.

In an embodiment of the second and/or third improvements, the supportcarries the image acquisition apparatus, but does not define a retractoropening to be surrounded by the lips of the patient in the serviceposition. A dental retractor, independent of the support, may be worn bythe patient or not.

Of course, the features of the various main refinements of the inventionand of the improvements may be combined (as far as the combined featuresare technically compatible).

Regardless of the main refinement or of the improvement underconsideration, a device according to the invention preferably has one ormore of the following optional features:

-   -   the support defines a chamber that is in communication with the        outside via the retractor opening and via an acquisition opening        through which the acquisition apparatus fastened by said        fastening means receives said composite image;    -   the support is telescopic so that the distance between the        retractor opening and acquisition opening is variable;    -   the device includes at least two of said mirrors that are        oriented perpendicularly to one another and each returning a        reflected image of the retractor opening, each of said reflected        images being represented in said composite image;    -   the means for fastening the acquisition apparatus to the support        can be deactivated;    -   the means for fastening the acquisition apparatus and/or the        dental retractor to the support are chosen from the group        consisting of a clip fastener, a self-gripping strip, clamping        jaws, a screw, a magnet, a cover, a complimentary shape between        the support and the acquisition apparatus, and an elastic        member;    -   the device includes means for fastening the dental retractor to        the support, which means can be deactivated, the dental        retractor thus being able to be removably fastened to the        support;    -   the dental retractor includes tabs which, in a position in which        the dental retractor is mounted on the support, are inserted        into respective profiled compartments of the support, each        compartment having a generally U-shaped cross section, the        opening of the U preferably facing upward or downward in a        service position in which the dental retractor is positioned on        the mouth of a patient holding his or her head vertically;    -   in said mounted position, the dental retractor is kept flexed,        bearing elastically on the support;    -   the support includes one or more, preferably two, hooks        configured to accommodate the dental retractor in said mounted        position;    -   the light source is configured so as to project a reference        frame toward the retractor opening;    -   the device includes a monitoring module configured to monitor        the properties of the radiation emitted by the light source,        preferably as a function of the luminous radiation received by        the retractor opening;    -   the monitoring module is configured to control the light source        so that more than 50%, more than 70%, more than 90%, or even        substantially 100% of the intensity of the radiation received by        the retractor opening comes from the light source;    -   the device includes a processing module in which the colour and        translucence properties of the colorimetric and translucence        calibration charts are recorded, respectively, the processing        module comprising program code instructions for correcting an        image representing said calibration charts so that the        representations of said calibration charts on the image have        said color and translucence properties;    -   the support is made in a fibrous material, preferably a        cellulosic material;    -   the support carries information, preferably guiding information        to guide the patient during the acquisition of images and/or        advertising information.

The invention also relates to:

-   -   a computer program, or “app” and in particular a specialized        mobile phone app, comprising program code instructions for        guiding imaging, and in particular, preferably, for        -   specifying to an operator the number of updated images to be            acquired, and/or        -   guiding an operator to position the image acquisition            apparatus in a predetermined position relative to the            retractor opening, for instance to take a photo “from the            right side”, and/or        -   guiding an operator to position his teeth in a predetermined            position relative to the image acquisition apparatus, for            instance to take a photo “from the right side”, in            particular when the image acquisition apparatus is immobile            relative to the ground, and/or        -   guiding an operator during an adjustment to the geometry of            the support and/or when orienting the mirror and/or when            positioning the mouth of the patient on the dental            retractor, and/or        -   controlling one or more actuators that are capable of            modifying said geometry, in particular modifying the length            of the support, and/or said orientation of the mirror;    -   a computer medium on which such a program is recorded, for        example a memory or a CD-ROM; and    -   a personal device, in particular mobile phone or a tablet, on        which such a program is loaded.

The computer program may, in particular, use a neural network, andgenerally artificial intelligence.

The invention also relates to an imaging kit including:

-   -   an imaging device according to the invention; and    -   an image acquisition apparatus fastened to the device in a        position in which the acquisition apparatus is oriented so as to        receive an image of patient's teeth, preferably an image of the        dental opening defined by the imaging device, preferably an        image of the retractor opening of a conventional dental        retractor, preferably fastened on the support of the imaging        device.

According to the first main refinement of the invention, the imageacquisition apparatus may thus acquire said composite image.

A kit according to the invention preferably has one or more of thefollowing optional features:

-   -   the acquisition apparatus is a mobile phone;    -   the mobile phone is fastened to the device in a position in        which a front camera of the mobile phone, i.e. a camera on the        same side of the mobile phone as the display screen of the        mobile phone, receives an image of a retractor opening of an        imaging device, and in particular an image of the dental        retractor fastened on the support of the imaging device;    -   the support comprises at least a slider on which the image        acquisition apparatus, preferably a mobile phone, is fastened        to, said slider preferably allowing for the sliding of the image        acquisition apparatus along at least one sliding direction in a        plane perpendicular to the optical axis of the image acquisition        apparatus;    -   the support comprises at least a first slider and a second        slider on which the image acquisition apparatus, preferably a        mobile phone, is fastened to, said first and second sliders        allowing for the sliding of the image acquisition apparatus        along first and second sliding directions, respectively, in a        plane perpendicular to the optical axis of the image acquisition        apparatus;    -   the image acquisition apparatus includes a computer program        according to the invention;    -   the image acquisition apparatus is configured to take multiple        photographs in succession, with different focal lengths, as a        result of a single trigger action.

In one preferred embodiment, the imaging device includes a detectionmember and the image acquisition apparatus includes a detector fordetecting the detection member that is configured so as to detect thedetection member when the detection member is less than 20 cm,preferably less than 10 cm, preferably less than 5 cm and/or preferablymore than 1 cm from the imaging device.

Preferably, the detector for detecting a detection member is configuredso as to detect the detection member only when the detection member isless than 100 cm, preferably less than 50 cm, preferably less than 30cm, preferably less than 20 cm, preferably less than 10 cm, preferablyless than 5 cm from the imaging device.

As will become more clearly apparent throughout the rest of thedescription, such an imaging kit advantageously allows the imageacquisition apparatus to react to the approach of the imaging device,and in particular to launch a computer program that is capable ofguiding said imaging.

The present invention also refers to a method to manufacture a supportof a device according to the invention, and optionally a dentalretractor of a device according to the invention, said method comprisingthe following steps:

A) manufacturing of a precursor of the support, and optionally of thedental retractor, in a first place, and providing said precursor to anoperator, preferably to a patient or an orthodontist, in a second placeaway from the first place, the distance between the first place and thesecond place being preferably greater than 1 km and/or less than 20 000km;

B) transformation of said precursor into said support, and optionallyinto said dental retractor.

In an embodiment, at step A), the precursor is in a cellulosic materialand has the shape of at least a sheet, preferably is a sheet ofcardboard, the thickness of which being preferably less than 6 mm andgreater than 05 mm, said precursor preferably representing folding linesand/or cutting lines and/or comprising tearable weakening lines.

If said precursor represents folding lines and/or cutting lines and/orcomprising tearable weakening lines, at step B), the operator cuts theprecursor along said cutting lines, and/or folds the precursor alongsaid folding lines, and/or tears the precursor along said weakeninglines, and/or rigidly fixes different parts of the precursor on eachother, by insertion of tabs, or lugs, into corresponding slots or withglue or with staples or clips or with a loops and hooks fasteners, asVelcro®.

In an embodiment, at step A), the precursor is a feedstock for a3D-printer, preferably a printer enabling an additive manufacturing, andthe operator is provided with a file to control said 3D printer totransform said feedstock into the support or a part of the support. Atstep B), the operator programs the 3D printer with said file so that the3D printer manufactures the support or said part of the support.

In an embodiment, at step A), the precursor is a set of parts of thesupport and is provided to the operator by mail, and, at step B), theoperator assembles said parts, manually or with a tool.

In an embodiment, at step A), the precursor is a support or a part ofthe support in a collapsed configuration and, at step B), the operatorextends the support or said part of the support to a fully extendedconfiguration.

Further Improvements

The invention also provides an imaging device comprising:

-   -   a support;    -   preferably a dental retractor, preferably independent of the        support, i.e. not fastened to the support, defining a retractor        opening; and    -   means for immobilizing an image acquisition apparatus to the        support.

In this embodiment, no dental retractor is necessarily fastened to thesupport. The support may be independent of the patient, i.e. the patientmay move without any displacement of the support.

The support preferably takes the form of a stand to be placed on theground or on a table, or to be rigidly fixed on a window glass or on amirror.

In a preferred embodiment, the height of the support is changeable sothat the altitude of the image acquisition apparatus relative to theground may be modified so that it substantially faces the head, andpreferably the mouth of the patient.

Preferably, the image acquisition apparatus rests on the support. Meansfor immobilizing the image acquisition apparatus to the support may besimple retaining means, like a rim or a hook.

The features of the various main refinements and improvements and of akit of the invention may be combined with this imaging device.

Preferably, the image acquisition apparatus is a mobile phone. Itpreferably has a front camera, i.e. a camera on the same side of themobile phone as the display screen of the mobile phone, and it isimmobilized relative to the support so that the front camera faces thepatient.

The scene which is observed by the front camera therefore appears on thedisplay screen of the mobile phone, which is exposed toward the patient.The patient can therefore advantageously visualize this scene andoptimize the angulation and/or the distance of the mobile phone toacquire images corresponding to his needs.

In a preferred embodiment, guiding information is provided on thedisplay screen, so as to help the patient to position himself correctly.This information is preferably a reference displayed in a position onthe display screen such that, when a part of the patient or a registermark of a reference frame added to the patient, in particular aconventional dental retractor, matches the reference on the displayscreen, for instance is superimposed or completes the reference on thedisplay screen, the preview image is according to a predeterminedviewing angle and/or a view at a predetermined distance, so that theimage acquisition apparatus is positioned according to targetacquisition conditions.

Preferably, the reference is chosen from a group consisting of

-   -   a point,    -   a geometrical shape,    -   a colored zone, for instance of a same color as said register        mark,    -   a shape identical to a shape of said register mark or of said        part of the patient,    -   a shape complementing a shape of said register mark or of said        part of the patient,    -   a line intended to be aligned with the general direction of the        join between the upper teeth and the lower teeth when the teeth        are clamped by the patient,    -   a vertical line intended to be aligned with the join between the        two upper incisors,    -   marks corresponding to the position of the eyes or taking the        form of an outline in which the mouth or the face of the patient        must be positioned,    -   a two-dimensional digital model or a three-dimensional digital        model of a human part, specific to the patient or not,        preferably representing lips, a mouth or teeth, in particular a        two-dimensional or a three-dimensional digital model of a dental        arch, preferably a two-dimensional or a three-dimensional        digital model of a dental arch or of the mouth or of the lips of        the patient,

and

-   -   combinations of these references.

The invention also refers to a method to acquire an image with a kitaccording to the invention,

the image acquisition apparatus being preferably a mobile phone andhaving a front face comprising a display screen and preferably a frontcamera, and a back face, opposite to the front face and comprising aback camera, and

the support of the imagine device, preferably in the form of a box,having a lateral wall defining a chamber in communication with theoutside via a retractor opening and an acquisition opening through whichthe acquisition apparatus, after it has been fastened to the support,receives an image of the retractor opening.

According to a first embodiment, said method comprises the followingsteps:

a) the patient fastens said mobile phone so that the back camera of themobile phone observes the retractor opening through the acquisitionopening;

b) the patient put the lips of the patient around the retractor opening,so that patient's teeth are visible through said retractor opening;

c) preferably, the display screen provides guiding information and thepatient observes the reflection of the display screen on a mirror andmodifies, according to said guiding information, the position of themobile phone to meet target acquisition conditions;

d) the patient acquires images with the mobile phone.

According to a second embodiment, said method comprises the followingsteps:

a′) preferably, the patient immobilizes the support relative to theground, preferably on a window glass or a mirror;

b′) the patient immobilizes the mobile phone relative to the support, toimmobilize it relative to the ground, preferably he places the mobilephone on the support, preferably so that the front camera of the mobilephone substantially faces the patient;

c′) optionally, the patient puts his lips around the retractor opening,preferably defined by a dental retractor, or uses his fingers or a toolsuch as a spoon to put his lips apart, so that patient's teeth arevisible;

d′) preferably, the display screen provides guiding information and thepatient observes the guiding information on the display screen;

e′) the patient modifies, preferably according to said guidinginformation, the position of his head to meet target acquisitionconditions, and in particular to reach a target position and a targetorientation relative to the mobile phone; and

f′) the patient acquires images with the mobile phone.

The target acquisition conditions preferably correspond to specificimages to be acquired, for instance to images to be taken from the left,from the right or in face of the patient's teeth. They are predeterminedand may be stored in the mobile phone or sent to the mobile phone.

Guiding the movement of the patient, the mobile phone being immobilizedrelative to the ground, rather than guiding the movement of the mobilephone makes it possible to use a very simple support.

The support may in particular be a simple casing, provided with one orseveral suction cups enabling the fixing on a glass panel. It may be adesk or a console.

It is preferably made of plastic and/or in a fibrous material,preferably in a cellulosic material such as cardboard. It may be sent tothe patient by mail, or a template of the support may be sent to thepatient by email, or made available to the patient on Internet.

In a preferred embodiment, at step b′), the patient modifies thealtitude of the mobile phone relative to the ground so that itsubstantially faces the head, and preferably the mouth of the patient.Preferably, the patient modifies the height of the support to change thealtitude of the mobile phone.

Definitions

A “main refinement of the invention” defines a particularly remarkableoptional feature.

A “patient” is understood to mean any person for whom a device accordingto the invention may be implemented, whether this person is sick or not,or whether this person is currently being treated or not. A deviceaccording to the invention may be used for an animal other than a humanbeing.

A “mobile phone” is a device weighing less than 500 g, provided with asensor enabling it to capture images, capable of exchanging data withanother device more than 500 km away from the mobile phone, and capableof displaying said data, and in particular said images.

The “support” is the part of the imaging device on which the imageacquisition apparatus is fastened to or immobilized. A dental retractorintended to maintain the mouth of a patient at least partly opened maybe fastened to the support or be integral with the support. Theretractor opening is the opening defined by the dental retractor,through which patient's teeth may be observed by the image acquisitionapparatus. Preferably, the support and the dental retractor define achamber which opens outwardly through an acquisition opening and theretractor opening.

In the service position, the retractor opening faces the patient's teethand is surrounded by the patient's lips. Whether the dental retractor isfastened to the support or integral with the support, it should be rigidenough to push the lips away from the teeth, so as to leave thepatient's teeth visible through said retractor opening.

The dental retractor may be formed as an integral part of the support.

The dental retractor may be the terminal portion of a tube, preferablyhaving a circular or oval section, or a ring. This tube may be asupport. The dental retractor may be an edge of the lateral walldefining said chamber on the side of the mouth.

Preferably, the dental retractor comprises a rim arranged in such a waythat the patient's lips may rest on it, in a retracted position. Thisrim may radially, the radiality being defined relatively to the axis ofthe retractor opening.

The dental retractor may be fastened, preferably rigidly, to the supportby any means.

The angulation of the acquisition opening or of the image acquisitionapparatus relative to the retractor opening is the angle between theaxis of the acquisition opening or the optical axis of the imageacquisition apparatus, respectively, and the plane of the retractoropening.

The distance between the acquisition opening and the retractor openingis the distance between their respective centres.

The axis L of a chamber defining a retractor opening and an acquisitionopening is the line which extends in the centre of the chamber betweenthe centres of the acquisition opening and of the retractor opening ofsaid chamber. It defines the direction along which the length of thechamber is measured.

A “transversal plane” is a plane which is perpendicular to the axis L.

The width of the chamber is the largest overall dimension in a crosssection of the chamber, i.e. in a section perpendicular to the axis L ofthe chamber.

The thickness of the chamber is the smallest overall dimension in across section of the chamber.

The “acquisition conditions” for acquiring an image of the teeth specifythe position and the orientation in space of an image acquisitionapparatus in relation to the teeth of the patient, and preferably thecalibration of this image acquisition apparatus, in order to acquire, atthe time of said acquisition, by direct observation, said image. Theacquisition conditions for acquiring a reflected image therefore specifythe position and orientation in space that the image acquisitionapparatus would have had to have taken, in the absence of the mirror, inorder to acquire the reflected image.

The “calibration” of an acquisition apparatus consists of the set ofvalues of the calibration parameters. A “calibration parameter” is aparameter intrinsic to the acquisition apparatus (unlike its positionand its orientation), the value of which influences the image acquired.For example, the aperture is a calibration parameter that modifies thedepth of field. The exposure time is a calibration parameter thatmodifies the luminosity (or the “exposure”) of the image. The focallength is a calibration parameter that modifies the viewing angle, i.e.the degree of “zoom”. The “sensitivity” is a calibration parameter thatmodifies the reaction of the sensor of a digital acquisition apparatusto incident light.

Preferably, the calibration parameters are chosen from the group formedby the aperture, the exposure time, the focal length and thesensitivity.

What is meant by an “image” is a two-dimensional image such as aphotograph. An image is made up of pixels. The acquired images areextraoral images, i.e. taken from the outside of the patient's mouth.

What is meant by an “updated image” is an image acquired by an imageacquisition apparatus. A composite image, according to the first mainrefinement of the invention, is an example of an updated image.

The term “fasten” means “fix rigidly”. The term “fasten” does notnecessarily mean “fix definitively”. The term “immobilization” includesa fixation which is rigid or not. In particular, an image acquisitionapparatus which rests on a support is regarded as immobilized on thesupport.

The terms “comprise”, “include” and “have” should be interpreted broadlyand without limitation, unless specified otherwise.

BRIEF DESCRIPTION OF THE FIGURES

Additional features and advantages of the invention will become furtherapparent upon reading the following detailed description and fromstudying the attached drawing, in which:

FIG. 1 shows, in perspective, a device according to the invention, seenthrough the side of the dental retractor;

FIG. 2 shows, in perspective, a device according to the invention shownfrom the acquisition opening side;

FIG. 3 shows an example of a composite image;

FIGS. 4a, 4b and 4c show the device of FIG. 1 seen from above, seen fromthe acquisition opening side and seen from the retractor opening side,respectively;

FIGS. 5a and 5b show the device of FIG. 2 with the support in retractedand deployed positions, respectively;

FIGS. 6a, 6b and 6c show, in perspective (FIGS. 6a and 6b ) and fromabove (FIG. 6c ), the portion of the support of a device according tothe invention on which a dental retractor may be mounted, as shown inFIG. 6 b;

FIG. 7 shows a kit according to the invention comprising a side view ofan imaging device according to the invention;

FIG. 8 illustrates how a device according to the second improvement maybe used;

FIG. 9 shows different views of a kit according to the invention, thedevice being according to the first improvement. The dental retractor isnot represented.

In the various figures, identical or analogous members have been denotedby the same references.

DETAILED DESCRIPTION

Device

The imaging device 10 shown in FIG. 1 includes a support 12, taking theform of an, optionally telescopic, box, a dental retractor 14,preferably at least one mirror 16, and fastening means 18 of an imageacquisition apparatus 19, shown in FIG. 2.

In one embodiment, the support 12 includes a male portion 12 a and afemale portion 12 b that are mounted so as to slide one inside theother, along a retractor axis X, between retracted (FIG. 5a ) anddeployed (FIG. 5b ) positions.

In one embodiment, a scale is arranged on the male portion 12 a of thesupport. Preferably, this scale provides indications facilitating theadjustment of the length, along the X axis, of the support 12, forexample by bearing a mark for each type of image acquisition apparatus.

The support 12 defines a chamber 20, the length of which along the Xaxis depends on the relative position of the male and female portions ofthe support 12 when the box is telescopic, or is constant.

In one preferred embodiment, the box is not telescopic (FIG. 7). Whenthe box is not telescopic, the distance between the retractor andacquisition openings is advantageously constant. The analysis of theupdated images is facilitated thereby. Furthermore, this embodiment isadvantageously simple, inexpensive and ergonomical.

In the embodiment shown, the chamber 20 is in communication with theoutside at two opposite end faces of the support 12, via a retractoropening 24 and an acquisition opening 26, respectively.

The lateral wall 30 of the support 12, which extends between the two endfaces, is preferably substantially cylindrical along the X axis, andpreferably rectangular in cross section.

In one embodiment, the support 12 is provided with a window throughwhich light from the surroundings may reach inside the chamber 20 inorder to illuminate the teeth.

Preferably, however, the chamber 20 is only in communication with theoutside via the retractor opening and acquisition opening.

The box thus composed may for example be made of plastic or of a fibrousmaterial, preferably in a cellulosic material such as cardboard.

The fastening means 18 are configured so that the image acquisitionapparatus may be fastened in an acquisition position in which itsobjective faces the acquisition opening 26, or else obturates theacquisition opening 26.

The means 18 for fastening the acquisition apparatus to the support 12may be of any type. Preferably, they allow rigid fastening. Preferably,they can be reversibly deactivated, i.e. the user may fix theacquisition apparatus to, and dissociate the acquisition apparatus from,the support at will.

Preferably, the fastening means 18 of the acquisition apparatus arechosen from the group consisting of clip-fastening means, self-grippingstrips of Velcro® type, clamping jaws, screws, magnets, elastic members,and complementarity of shape between the support and the acquisitionapparatus. In the embodiment shown in FIG. 2, the fastening means 18consist of a cover that may be clamped against the support 12.

In one embodiment, the fastening means 18 of the acquisition apparatusare suitable for fastening a conventional camera, for example of reflextype.

Preferably, as shown in FIG. 7, the means 18 for fastening theacquisition apparatus are magnetic. In particular, one or more magnets18 ₁, 18 ₂ may be provided on the support and one or more metal partsmay be fastened to the image acquisition device so as to cooperate withthe one or more magnets. In particular, a metal plate 32 may be heldfast on the image acquisition apparatus, preferably sandwiched betweenthe acquisition apparatus and a protective shell that is fastened to theacquisition apparatus.

In one embodiment, the acquisition apparatus includes multiple metalparts and/or the support includes multiple magnets.

Advantageously, it is therefore sufficient for the operator to bring theacquisition device close to the support for the acquisition apparatus tobe fastened to the support. The use of magnetic fastening also allowsvery precise and reliable fastening, even when the operator is notlooking at the support or the acquisition apparatus.

Preferably, the means 18 for fastening the acquisition apparatus, and inparticular the one or more magnets and metal parts, are configured sothat the acquisition apparatus may be fastened to the support in onlyone predetermined position. The fastening of the acquisition apparatustherefore requires no particular training for the operator.

Where appropriate, visual guides may be present to guide the operatorand to ensure the correct positioning of the acquisition apparatus.

The dental retractor 14 may have the features of conventionalretractors. A conventional retractor conventionally includes a rim 34extending around the retractor opening 24 and arranged in such a waythat the patient's lips may rest on it, leaving the patient's teethvisible through said retractor opening. In the embodiment shown, thedental retractor 14 also includes lobes 36 that are arranged so as tospread the cheeks away from the teeth and right 38 a and left 38 b tabs,which are substantially perpendicular to the X axis, facilitating thehandling thereof.

The rim 34 has the shape of a channel configured to hold the patient'slips.

The dental retractor 14 is preferably made of a biocompatible material,for example of a plastic material.

Preferably, the dental retractor is removable, i.e. it may be mounted onand dismounted from the support by the operator. Advantageously, thesame support may therefore be used for multiple retractors, and inparticular for multiple retractors of different sizes.

The means for fastening 15 the dental retractor to the support may befor example clip-fastening means, self-gripping strips of Velcro® type,clamping jaws, screws, magnets, complementarity of shape between thesupport and the dental retractor, and elastic members like an elasticband.

In one embodiment, the dental retractor 14 is fastened by means ofinsertion of one of the right 38 a and left 38 b tabs into a compartmentof the support, then clipping the other tab onto the support.

In one embodiment, the dental retractor 14 is fastened by means ofclipping the tabs into respective compartments of the support.

In one preferred embodiment, illustrated by FIG. 6, the means forfastening 15 the dental retractor to the support include a hook ontowhich the dental retractor 14 may be hooked. The means for fastening 15the dental retractor to the support preferably include a right hook 40 aand a left hook 40 b that are arranged so as to accommodate the right 38a and left 38 b transverse tabs of the dental retractor, respectively.Since the right and left hooks are similar, only one hook is describedin detail below.

Preferably, said hook protrudes from the rear face 44 of the support,substantially perpendicularly to the X axis, as shown in FIG. 1. Therear face 44 is preferably defined by a plate 47 (FIG. 6a ) that isfastened to an edge of the lateral wall 30 of the support 12.

Preferably, the hook takes the form of an angle 45. The angle preferablyincludes first and second wings that are perpendicular to one another.The first wing 48 ₁, fastened to the rear face 44 of the support, ispreferably substantially parallel to the X axis and the second wing 48 ₂is preferably substantially perpendicular to the X axis and, preferably,extends upward from the first wing. Along with the rear face 44 of thesupport, the angle 45 defines a compartment with a U-shaped profile, themain, upward-oriented opening 46 of which is sized so as to accommodatea tab of the dental retractor. Again preferably, the profiledcompartment is open at its two right and left ends via right 48 and left50 openings through which a tab of the dental retractor may be slid intothe hook, i.e. between the rear face 44 of the support and the secondwing 48 ₂ of the angle 45, until abutting against the first wing 48 ₁.

Preferably, the hooks are configured so that the dental retractor may beinserted therein only by force, preferably by elastically opening thehooks.

Preferably, the hooks are configured so that the dental retractor may beinserted therein without being deformed, preferably by flexing around anaxis Y that is substantially perpendicular to the X axis, preferablysubstantially vertical in the service position.

Again preferably, in the position in which the dental retractor ismounted on the support, fastening means 15 hold the dental retractorflexed around the Y axis.

In the embodiment of FIG. 6 (FIG. 6c ), the axes Z_(a) and Z_(b) of theangles of the left and right hooks are thus inclined with respect to atransverse plane P that is perpendicular to the X axis, while the rightand left tabs of the dental retractor are substantially coplanar whenthe dental retractor is at rest, dissociated from the support. The widthof the main openings 46 of the right and left hooks is substantiallyidentical to the thickness of the right and left tabs of the dentalretractor, respectively, which obliges the operator to flex the dentalretractor around the Y axis in order to insert these tabs into thesehooks. The shape of the hooks then prevents the dental retractor fromreturning to its rest position.

The elastic bearing of the dental retractor on the support thus obtainedadvantageously favors its being held in position.

The means 15 for fastening the dental retractor are preferably magnetsor comprises magnets and metallic inserts cooperating with said magnets.Preferably, the magnets are rigidly fixed to the support and cooperatewith metallic inserts rigidly fixed to the dental retractor. The samesupport may advantageously be used with different retractors, possiblyhaving different sizes, with a limited cost.

Preferably, the dental retractor comprises two magnets or metallicinserts, preferably metallic inserts, preferably made in inox, locatedon the right and on the left of the retractor opening. Metallic insertshave advantageously a better resistance to high temperatures.

In an embodiment, the dental retractor comprises a magnet in a firstlocation, for instance on the right of the retractor opening, and ametallic insert in another location, for instance on the left of theretractor opening, and the support comprises corresponding metallicinsert and magnet. Advantageously, the patient cannot invert theposition of the dental retractor, i.e. to put the lower part of thedental retractor above its upper part.

It is also possible to use magnets on the dental retractor and on thesupport. The magnets are preferably oriented so that the dentalretractor may only be fastened to the support in one predeterminedposition.

In one preferred embodiment, the device includes a light source 51 thatis preferably oriented toward the retractor opening 24 (FIG. 5a ) so asto illuminate the teeth of the patient through the retractor opening 24.The light source 51 may in particular emit white light, monochromaticlight, infrared radiation or, preferably, ultraviolet radiation.

The light source 51 may be a flash.

The light source is preferably fastened to the box. It preferablycomprises LEDs.

In one embodiment, the light source 51 is configured so as to project,onto the teeth, through the retractor opening 24, a reference frame,preferably a laser grid. Advantageously, the representation of areference frame on the images facilitates the determination of the shapeof the teeth. A first estimation of the shape of the teeth is thuspossible without implementing the method described in PCT/EP2015/074896.

In one embodiment, threading is formed on the lateral wall 30 of thebox, preferably on the lateral wall of the female part 12 b of the box.The threading is preferably shaped so as to allow the support to befastened to a camera tripod.

In one embodiment, the device also includes an acquisition cover and aretractor cover, which covers are shaped so as to selectively obturatethe acquisition opening and the retractor opening in order to facilitatethe storage of the device. Preferably, the retractor cover is shaped soas to selectively obturate the retractor opening after dismounting theretractor.

According to the first main refinement of the invention, the deviceincludes a mirror 16.

The mirror 16 is fastened to the inner face of the lateral wall 30.

The mirror 16 is preferably planar.

The number and the shape of the mirrors are not limiting. In particular,the mirror may be rectangular, spherical, oval, octagonal or hexagonalin shape.

In the embodiment shown, mirrors 16 cover the entire inner face of thelateral wall of the chamber 20, at least in the female portion 12 b ofthe support 12 and, preferably, also in the male portion 12 a of thesupport.

In one embodiment, the device includes four mirrors each positioned onone of the four faces of the lateral wall of the support, and inparticular of the female portion 12 b and, preferably, of the maleportion 12 a of the support. In one preferred embodiment, each mirrorentirely covers the face of the support 12 over which it extends.

The length of a mirror may be greater than 3 cm, greater than 5 cmand/or smaller than 30 cm, smaller than 20 cm, smaller than 15 cm, orsmaller than 10 cm. The width of a mirror may be greater than 2 cm,greater than 3 cm and/or smaller than 10 cm or smaller than 8 cm.

In the embodiment shown, the mirrors are fastened to the support,preferably definitively, for example by means of an adhesive.

The mirror 16, preferably each mirror 16, preferably extends in parallelto the X axis. In the embodiment shown, the mirror 16 extendperpendicularly to one another, pairwise.

The simultaneous presence of a mirror and of a light source 51 isparticularly advantageous since it makes it possible to acquire imagesof the teeth that simultaneously show the reflection of the light source51 off the teeth, but also the reflection of the fictive light sourceobtained by reflection of the light source 51 by the mirror. Analyzingthe relative position of these reflections in the images advantageouslymakes it possible to roughly determine the orientation of the surface ofthe teeth returning them, as well as the position of this surface withrespect to the acquisition apparatus.

According to the second main refinement of the invention, the deviceincludes a colorimetric calibration chart 52 and/or a translucencecalibration chart 54 that is fastened to the support, preferably in thechamber 20, or to the retractor cover, or to the mouth retractor.

The number and the shape of the calibration charts are not limiting. Inone embodiment of FIG. 6a , the support bears for example threecolorimetric calibration charts 52 and three translucence calibrationcharts 54.

Advantageously, the colorimetric 52 and translucence 54 calibrationcharts make it possible, for each image, to correct hue errors specificto each image acquisition apparatus.

The colorimetric 52 and translucence 54 calibration charts alsoadvantageously make it possible to determine the exact colors andtranslucence of the teeth or of the gums, thereby allowing any variationin these properties to be detected.

Preferably, the colorimetric 52 and translucence 54 calibration chartsare fastened in proximity to the retractor opening, preferably at lessthan 5 cm, less than 3 cm, less than 1 cm from the retractor opening.Preferably, the colorimetric 52 and translucence 54 calibration chartsare fastened substantially in the plane of the retractor opening, asshown in FIG. 6 a.

Preferably, the monitoring module 60 monitors the properties of theradiation emitted by the light source 51, preferably as a function ofthe luminous radiation received by the retractor opening. A light sensormay be provided, in proximity to the retractor opening, for the purposeof evaluating the luminous radiation received by said retractor opening.

In one embodiment, the monitoring module 60 controls the power of thelight source 51 so that more than 50%, more than 70%, more than 90%, oreven substantially 100% of the intensity of the radiation received bythe retractor opening comes from the light source 51.

According to the third main refinement of the invention, the supporttakes the form of a box that is in communication with the outsidesubstantially only via the retractor and acquisition openings.Advantageously, the influence of the outside environment on the box islimited, thereby allowing images to be acquired under constantconditions. Furthermore, when the device includes a light source 51, aclosed box advantageously makes it possible to limit the power of thelight source 51.

Preferably, the total area of the openings other than the spacer andacquisition openings represents less than 10%, preferably less than 5%,preferably less than 1% of the area of the lateral wall of the boxdelimiting the chamber 20. Preferably, the box includes no such “otheropenings”.

In one embodiment, the lateral wall delimiting the chamber 20 is formedor consists of a material that does not allow the content of the chamber20 to be accurately discerned, including the arches of the patient whenthe device is in a service position in which a patient has placed his orher lips in the channels of the dental retractor. Advantageously, such alateral wall specifically completely protects the user's privacy whileacquiring the updated images.

In one embodiment, the lateral wall is translucent.

Preferably, the lateral wall is opaque. Advantageously, the inner volumeof the chamber receives substantially no light from the outside, therebyguaranteeing constant conditions for acquiring updated images.

According to the first improvement of the invention, the support has alateral wall defining the chamber, and the lateral wall comprises arigid portion defining the acquisition opening, and a deformable portiondefining the retractor opening.

By “rigid”, it is meant that, after the fastening of the imageacquisition apparatus, the rigid portion substantially keeps its shapewhen it is manipulated by an operator to acquire images.

By “deformable”, it is meant that the shape of the deformable portionmay be substantially modified, preferably without any tool, by theoperator, in particular to change the distance between the centre of theacquisition opening and the centre of the retractor opening and/or theangulation of the acquisition opening relatively to the retractoropening.

The deformable portion may in particular be extendable, as according tothe second improvement of the invention.

The deformable portion may be used to modify the acquisition conditionsfor acquiring an image.

The deformable portion may be used to improve the comfort of thepatient. In particular, when a conventional retractor is fixed onto arigid support, its stiffness may lead to a determined shape which doesnot meet the anatomies of all patients. The deformable portion allowsfor an adaptation to the anatomy of each patient.

The deformability also enables the fastening of conventional dentalretractors having different sizes.

The deformability of the deformable portion may be limited. Inparticular, the lateral wall in the deformable portion is preferablyconfigured so that it only allows for

-   -   a change of the angulation of the acquisition opening relative        to the retractor opening of less than 30°, less than 20°, less        than 10° and/or greater than 1°, and/or    -   a change of the distance between the centre of acquisition        opening and the centre of the retractor opening of less than 5        cm, less than 3 cm, less than 2 cm, less than 1 cm, and/or        greater than 0.1 cm.

The deformable portion may in particular be a bellow, in particular abellow as described previously, or a flexible skirt or a flexible bead.

When the deformable portion is used to improve the comfort of thepatient, it is preferably fixed to the dental retractor.

According to the second improvement of the invention, the support,preferably a lateral wall defining a chamber of the support, isextendable, preferably manually, and preferably without any tool, from acollapsed configuration.

A “collapsing” is an operation during which the support, preferably thelateral wall, is made more compact. The collapsing may in particularresult in portions of the support, preferably of the lateral wall, beingpushed on each other so as to be adjacent to each other.

An “extension” is the opposite operation.

In the collapsed configuration, the device is advantageously morecompact. Consequently, the storage and shipment costs are reduced.

In an embodiment, at least one dimension of the support, and inparticular of the chamber defined by the lateral wall, has a “collapsed”value D_(c), in the collapsed configuration, and an “extended” valueD_(e), greater than the collapsed value D_(c), in a fully extendedconfiguration. Preferably, the ratio D_(c)/D_(e) is less than 0.5,preferably less the 0.4, preferably less the 0.3, preferably less the0.2, preferably less the 0.1.

Preferably, the collapsed value D_(c) is less than 5 cm, preferably lessthan 4 cm, preferably less than 3 cm.

Said dimension may be the length, measured along the axis L of thechamber, or the width or the thickness, preferably the length or thewidth, preferably the length of the chamber.

Of course, the lateral wall may be extendable along several dimensions,for instance along the length and along the width of the support.

Preferably, the lateral wall is also collapsible from the fully extendedconfiguration to the collapsed configuration.

The collapsing may result from the insertion of rigid parts of thelateral wall into each other, in a telescopic way. However, preferably,it results from a deformation of a deformable portion of the lateralwall, preferably from a folding of the lateral wall.

Preferably, the lateral wall comprises predetermined folding linesacting as hinges to modify said dimension. The lateral wall ispreferably foldable along its length. The folding lines are preferablyextending in at least one transversal plane.

In a preferred embodiment, the lateral wall comprises a bellow,preferably configured to allow an extension, and preferably a collapsingalong the axis of the acquisition opening. The bellow preferablycomprises more than 1, preferably more than 2, preferably more than 3,preferably more than 4, and/or preferably less than 10, preferably lessthan 8, preferably less than 7, preferably less than 6 levels.

In an embodiment, the lateral wall comprises an elastic part. Pulling onsaid elastic part allows for an extension of the lateral wall to modifysaid dimension.

A “path” is a succession of intermediate configurations of the lateralwall between the collapsed configuration and a fully extendedconfiguration.

Preferably, in a fully extended configuration and/or in an intermediateconfiguration, preferably in any fully extended configuration and/or inany intermediate configuration, the angulation and/or the distancebetween the acquisition opening relative to the retractor opening may bedifferent than in the collapsed configuration. Therefore, themodification of the shape of the lateral wall makes it possiblemodifying the acquisition conditions for acquiring an image.

In an embodiment, the orientation of the retractor opening relative tothe acquisition opening may be easily modified, so that images may beacquired with different angulations.

Advantageously, a bellow allows for an extension and a collapsing of thelateral wall, but also provides some flexibility for the acquisition ofimages. It also provides several fully extended configurations.

Preferably, in a fully extended configuration and/or in an intermediateconfiguration, preferably in a fully extended configuration and/or inany intermediate configuration, the support has a stable shape, i.e.when the imaging device is hold, only by the dental retractor, by thepatient, the retractor opening extending vertically, the lateral wallkeeps its shape.

Preferably, in the fully extended configuration and/or in anintermediate configuration, preferably in any fully extendedconfiguration and/or in any intermediate configuration, the support hasa stable shape even when it carries a mobile phone at the terminal endof the support defining the acquisition opening. Advantageously, thedevice is easier to use.

Preferably, the lateral wall is configured so that the angulation of theacquisition opening relative to the retractor opening is limited toremain less than 100°, preferably less than 90°, preferably less than80°, preferably less than 70°, and/or greater than 10°, preferablygreater than 15°, and/or the distance between the centre of acquisitionopening and the centre of the retractor opening is limited to remaingreater than 5 cm and preferably less than 30 cm, 25 cm or 20 cm.Advantageously, the acquisition conditions for acquiring an image arethereby limited.

In an embodiment, the lateral wall is configured so that the flexibilityof the lateral wall depends on its configuration. Put differently, it ismore or less difficult to change the shape of the lateral wall, and ofthe chamber, depending on its configuration. The operator may therebyidentify privileged angulation(s) and/or distance(s), i.e. privilegedconfiguration(s) of the lateral wall. The privileged configurations ofthe lateral wall may in particular correspond to predeterminedacquisition conditions for acquiring images, for instance for acquiringimages “from the right”, “from the left” and “in face” of the patient.

The acquisition of images is advantageously made easier and faster.

In an embodiment, the lateral wall comprises a bellow having a variablethickness so as to define said privileged configurations.

The lateral wall may be extendable along its all length or along a partof its length.

FIG. 8 illustrates how a device according to the second improvement maybe used.

FIG. 9 illustrates an example of a device according to the first andsecond improvements of the invention.

In this embodiment, the support comprises a rigid portion 64 whichdefines the acquisition opening 26, and a deformable portion 66 whichdefines the retractor opening 24.

In an embodiment, the bellow may be pushed inside the rigid proximalpart 64, which makes the device more compact and protect the bellowswhen the device is not used.

The rigid portion 64 comprises a rigid tube 70 and means 18 forfastening the acquisition apparatus to the support 12.

The means 18 for fastening the acquisition apparatus to the support 12may be of any type. Preferably, they allow rigid fastening. Preferably,they can be reversibly deactivated, i.e. the user may fix theacquisition apparatus to, and dissociate the acquisition apparatus from,the support at will. They may be chosen from the group consisting ofclip-fastening means, self-gripping strips of Velcro® type, clampingjaws, screws, magnets, complementarity of shape of the support and ofthe acquisition apparatus, and elastic members.

In the represented embodiment, they define rails into which the imageacquisition apparatus 19, which is here a mobile phone, is inserted,slightly in force. These means could also be a pair of jaws elasticallycompressing the mobile phone.

Advantageously, the position of the mobile phone along said rails orperpendicular to the compression direction of the jaws can be modified.

The rigidity of the rigid portion makes the fastening of the imageacquisition apparatus easier.

The tube 70, having preferably a rectangular cross-section, is similarto the above-described box, but does not define the retractor opening24. More precisely, it opens to the outside only via the acquisitionopening 26, through which the acquisition apparatus fastened to thesupport receives at least one image of the retractor opening 24. On theside opposite to the acquisition opening, the tube 70 is connected tothe collapsible part 66, through a common intermediate opening 72, sothat the lateral wall 30 defines a chamber which preferably opens towardthe outside only through the retractor opening and the acquisitionopening.

The length L₇₀ of the tube 70 is preferably greater than 5 cm, and/orless than 20 cm, preferably less than 15 cm, preferably less than 10 cm,so that it may be easily manipulated by the patient.

The deformable portion 66 comprises a bellow 76 and means 15 forfastening a dental retractor to the support 12.

The means 15 are two magnets 78, intended to cooperate with tworespective metal inserts rigidly fixed on the dental retractor. Othermeans 15 are possible, and in particular the fastening means describedhereabove for the image acquisition apparatus. Preferably, the means 15do not allow any substantial modification of the position of the dentalretractor once it has been fastened to the support 12.

The bellow 76 has four levels, a level corresponding to a respectivefolding line 80 on the outside of the bellow 76.

The rigid portion 64 and the deformable portion 66 together define thechamber 20. Laterally, the chamber 20 is delimited by the lateral wall30 which is partly defined by rigid portion 64 and partly defined by thedeformable portion 66.

In a preferred embodiment, at least in the collapsed configuration, thebellow 66 is partly (as represented in the section A-A of FIG. 9), orcompletely housed inside the tube 70. The tube advantageously protectsthe bellows.

In an embodiment, the bellow 76 also defines the acquisition opening.The intermediate opening 72 is then confused with the acquisitionopening 26.

The bellow 76 may be rigidly fixed on the rigid portion, in particularalong its edge defining the intermediate opening 72. It may also beslidably mounted on the rigid portion, so that it may move along theaxis of the tube 70. This embodiment provides protection of the bellowwith a maximal extension.

In an embodiment, which is not preferred, the bellow 76 cross the tube70 and protrudes on both sides of the tube 70. The fixing means 15 and18 must then be provided on the bellow.

Preferably, the image acquisition apparatus, in particular a mobilephone, has a program to guide the patient toward one or severalpredetermined acquisition conditions and/or to position the optical axisof the image acquisition apparatus relatively to the retractor openingin a predetermined position. This program preferably uses an artificialneural network.

According to the third improvement, the support, preferably at least apart of the lateral wall, is at least partially, preferably completelyin a material which is degradable by composting and/or biodegradation,preferably according to the European standard EN 13432, preferably witha residue of less than 10%, preferably less than 5%, preferably less 1%in 6 months.

Preferably, said material support is in a fibrous material, preferably acellulosic material is cardboard or paper. The environmental impact ofthe support is advantageously limited.

Preferably, the support weighs more the 5 g and/or less than 100 g. Theimpact of its shipping on the environment is therefore limited.

Manufacturing

The manufacture of the support of an imaging device according to theinvention, and in particular a device according to the first, secondand/or third improvements of the invention, and optionally of the dentalretractor, is preferably achieved, from a precursor of said support, inparticular when the imaging device is to be manufactured, for instance,less than 1 month, less than 2 weeks, less than 1 week or less than 1day before being used by the patient.

A “precursor of a support” is a part, or a plurality of parts, or“precursor part(s)”, which may be transformed by an operator to get thesupport.

In an embodiment, the precursor of the support, and optionally of thedental retractor, is (are) manufactured in a first place, and providedto the operator in a second place away from the first place, thedistance between the first place and the second place being preferablygreater than 1 km and/or less than 20 000 km.

Then, said precursor is transformed into said support, and optionallyinto said retractor.

The operator is preferably the patient or an orthodontist or a dentist,preferably the patient.

Without precursors, the acquisition of images by the patient normallyrequires that the patient meets the orthodontist to receive the imagingdevice, which is not comfortable for the patient. Alternatively, theimaging device may be sent to a patient, but this would generatesubstantial costs.

In an embodiment, the precursor comprises a precursor part

-   -   the shape of which is to be changed for the manufacturing of the        support, in particular by folding and/or bending, and/or    -   at least a dimension of which is to be changed for the        manufacturing of the support, in particular by cutting, for        instance with scissors, or by tearing, and/or    -   which needs to be assembled to at least one other part for the        manufacturing of the support, in particular by gluing and/or        stapling and/or clipping and/or fastening of a loops and hooks        fastener of the Velcro® type and/or inserting a tab of the        precursor part into a corresponding slot of said other precursor        part, or conversely.

The precursor part has preferably a plastic behaviour so that the newshape resulting from said folding and/or bending is stable. Preferably,the new shape is consolidated, for instance by gluing and/or staplingand/or clipping a first region of the precursor part to a second regionof the precursor part or of another precursor part, and/or by insertinga tab of said first region into a corresponding slot of said secondregion.

Preferably, the precursor part bears assembling information to make themanufacturing of the support easier. The assembling information may inparticular comprise

-   -   a text, for instance to list the operations required for the        manufacturing and/or to provide the number of an hot line,        and/or    -   visual signs, for instance arrows, warning signs, geometric        forms, for instance to indicate emplacements to glue or regions        to be assembled together,    -   folding lines, i.e. along which the operator is to fold the        precursor part, and/or    -   tearable weakening lines i.e. along which the operator is to        tear the precursor part, and/or    -   cutting lines, i.e. along which the operator is to cut the        precursor part.

Instructions for the manufacturing are preferably included in a manual,in a numeric form, for instance a video, or a paper form, which isprovided to the operator.

The precursor part may in particular have the shape of a sheet. Thethickness of the sheet is preferably less than 6 mm, preferably lessthan 5 mm, preferably less than 4 mm, preferably less than 3 mm, and/orgreater than 0.5 mm, preferably greater than 1 mm.

Preferably, the precursor part is in a cellulosic material, preferablyin paper or cardboard, in particular when it has the shape of a sheet.

In an embodiment, and in particular when the precursor has the shape ofone or several sheets, the precursor is provided to the operator bymail, preferably after being enclosed into an envelope.

To manufacture at least a part of the support from a precursor parthaving the shape of a sheet, the operator preferably cuts the precursorpart along cutting lines, and/or folds the precursor part along foldinglines, and/or tears the precursor part along weakening lines, and/orfixes different parts of the precursor part on each other and/or onother precursor parts, by insertion of tabs, or lugs, into correspondingslots or with glue or with staples or with clips or with a loops andhooks fastener of the Velcro® type.

In a preferred embodiment, the support is formed from one or severalsheets of cardboard or paper, optionally with glue, preferably withoutglue, like an origami. These sheets are named “precursor sheets”.

In a preferred embodiment, the precursors sheet(s) is (are) also used toform the dental retractor. The dental retractor is preferably integralwith the support.

In an embodiment, the precursor comprises one or several sheets ofcardboard to be cut by a cutting machine, for instance a laser cuttingmachine.

The cutting machine may be the property of the operator. The sheets ofcardboard may be sent to the operator by mail, or the operator may buythe sheets of cardboard locally.

The cutting machine and the sheets of cardboard may also be availablenear the location of the operator, for instance in a fabricationlaboratory.

The operator is provided, preferably via Internet or with an email, witha file to control a cutting machine to transform said sheets ofcardboard into a support. The format of the file is adapted to thecutting machine.

The file and the sheets of cardboard may be loaded in the cuttingmachine by the operator or by another person. The cutting machine isthen operated to manufacture the support or a part of the support, andpreferably the dental retractor.

In an embodiment, the precursor comprises a feedstock for a 3D-printer,for instance plastic pellets.

The 3D printer may be the property of the operator. The feedstock may besent to the operator by mail, or the operator may buy the feedstocklocally.

The 3D printer and the feedstock may also be available near the locationof the operator, for instance in a fabrication laboratory.

The operator is provided, preferably via Internet or with an email, witha file to control a 3D printer to transform said feedstock into asupport. The format of the file is adapted to the printer. It may inparticular be the format STL, OBJ, AMF, or 3MF.

The file and the feedstock may be loaded in the 3D printer by theoperator or by another person. The 3D printer is then operated tomanufacture the support or a part of the support, and preferably thedental retractor.

The following 3D-printing methods are well-known: «SLM®» (SelectiveLaser Melting), «DMLS» (Direct Metal Laser Sintering), «PS» (PowderSintering), Infrared sintering, «SLS®» (Selective Laser Sintering),«ALM» (Additive Layer Manufacturing), «CLAD» (Construction LaserAdditive Directe), «LFFM» (Laser Free Form Manufacturing), EBM (ElectronBeam Melting) from the Swedish company ARCAM, Laser Cusing from theGerman company Concept Laser, UAM (Manufacturing Additive Ultrasons) orLENS (Laser Engineered Net Shaping).

In an embodiment, parts of the support, and optionally of the dentalretractor, are provided to the operator, for instance by theorthodontist, and/or sent to the operator by mail, preferably afterbeing enclosed into an envelope.

Then, the operator assembles said parts, manually or with a tool,optionally with parts that he manufactured himself from a precursor.

In an embodiment, the support or parts of the support having a firstshape are provided to the operator, for instance by the orthodontist,and/or sent to the operator by mail, preferably after being enclosedinto an envelope.

Then, the operator transforms said support or said parts, manually orwith a tool, to give said a second shape. The first shape is preferablymore compact than the second shape.

In particular, the first shape may be in a collapsed configuration. Theoperator may extend the support to a fully extended configuration or toan intermediate configuration.

Imaging Kit

An imaging kit according to the invention includes an imaging deviceaccording to the invention and an image acquisition apparatus 19.

The image acquisition apparatus 19 preferably provides color images,and/or infrared images. Infrared images advantageously make it possibleto view the teeth with an excellent level of contrast.

Preferably, the image acquisition apparatus 19 is a personal devicecommonly available on the market, for example a mobile phone, a“connected” camera, a smartwatch, a tablet or a fixed or portablepersonal computer, including an image acquisition system, such as awebcam or a camera, preferably a digital camera. It preferably weighsless than 3 kg, less than 2 kg, less than 1 kg, less than 500 g,preferably less than 300 g.

The image acquisition apparatus 19 may be integrated within the support12 or, preferably, be fastened temporarily to the support 12, by virtueof the fastening means 18 of the acquisition apparatus.

In one preferred embodiment, the image acquisition apparatus includes aprocessing module 59 configured to guide the operator during the imagingoperation, in particular so that he or she adjusts the length of thesupport 12 appropriately and/or so that he or she correctly positionshis or her mouth on the dental retractor 14.

In one preferred embodiment, the imaging device includes a detectionmember 70 that a detector 72 of the image acquisition apparatus maydetect (FIG. 5a ).

Preferably, the detection member 70 and the detector 72 are configuredso that detection is possible only when the imaging device is in theimmediate proximity of the image acquisition apparatus. Advantageously,the image acquisition apparatus therefore does not react when theimaging device is remote therefrom. Preferably however, the detectionmember 70 and the detector 72 are configured so that the remotedetection is possible, preferably at a distance that is greater than 5cm, or even greater than 10 cm. Advantageously, the image acquisitionapparatus may thus react very quickly.

The position of the detection member on the support is not limiting.Preferably however, it is positioned less than 5 cm, preferably lessthan 3 cm, more preferably less than 2 cm from the edge of theacquisition opening. Advantageously, the acquisition apparatus is thusdetected only when the image acquisition apparatus is brought close tothe acquisition opening.

In one preferred embodiment, the detection member is a magnet and thedetector 72 of the image acquisition apparatus includes a magnetometer.A magnetometer is capable of detecting a change in the magnetic fieldsurrounding it, and is therefore capable of detecting the approach of amagnet.

Since mobile phones are generally provided with a magnetometer, theimage acquisition apparatus is preferably a mobile phone.

The detector 72 is configured so as to control the processing module 59,according to the detection of the detection member 70.

In one preferred embodiment, the detector 72 triggers the execution ofthe computer program loaded on the processing module 59 in the eventthat the detection member 70 is detected. It is therefore sufficient forthe operator to bring the image acquisition apparatus, preferably aphone, close to the support to be guided in his or her image acquisitionoperations. Such an embodiment advantageously allows an operator who hasreceived no prior training to acquire images.

Preferably, the image acquisition apparatus transmits a message inresponse to the detection of a detection member 70 by the detector 72.The message preferably relates to the use of the imaging device.Preferably, the image acquisition apparatus is configured to transmitmessages relating to the fastening of the acquisition apparatus, forexample by means of a voice message saying “place your camera againstthe blue face of the support”, and/or relating to the fastening of thedental retractor, for example by transmitting a voice message saying“bend the dental retractor to fasten it onto the green tabs”, and/orrelating to the timing of the updated images to be acquired, for exampleby transmitting a voice message saying “take three photos and send themto your orthodontist”.

The message may be purely informative. In one preferred embodiment, themessage transmitted by the image acquisition apparatus depends howeveron the interactions between the operator and the image acquisitionapparatus. For example, the image acquisition apparatus may transmit amessage saying “the camera is upside down/backwards” or “the camera isnot oriented correctly” or “your lips are not correctly positioned inthe retractor channel”.

The detection member and the detector thus facilitate the acquisition ofupdated images.

Preferably, the detector 72 and/or the detection member 70 also play arole in fastening the image acquisition apparatus to the support. Inparticular, the detection member 70 is preferably a magnet 18. The useof a magnet that serves both to detect and to fasten the imageacquisition apparatus is advantageously simple, inexpensive and verypractical.

Operation

The operation of the kit is directly evident from the description above.

It is described for the embodiment shown in FIG. 7.

Initially, the metal plate 32 is preferably fastened to the imageacquisition apparatus 19, in this instance under the protective shell ofa mobile phone.

As soon as the operator brings the image acquisition apparatus 19 closeto the acquisition opening 26, the metal plate 32 is attracted by themagnets 18 ₁ and 18 ₂, and cooperates with these magnets to fasten theimage acquisition apparatus in a predetermined position, suitable foracquiring updated images according to a predetermined framing. Inparticular, in this position, the objective of the image acquisitionapparatus is correctly positioned with respect to the acquisitionopening, preferably substantially in the centre of the acquisitionopening, and observes the inside of the chamber 20, in this position,the image acquisition apparatus 19 may observe both the direct image andthe reflected image.

Preferably, the mobile phone has a back camera, i.e. a camera on theside of the mobile phone opposite to the display screen of the mobilephone, and it is fastened to the support so that the back camerareceives an image of the retractor opening.

The scene which is observed by the back camera therefore appears on thedisplay screen of the mobile phone, which is exposed toward the outsideof the device. If the operator is facing a mirror, he can thereforeadvantageously visualize this scene, and optimize the angulation and/orthe distance of the mobile phone to acquire images corresponding to hisneeds.

Furthermore, on approaching the support, at least one of the magnets 18₁ and 18 ₂ of the support is detected by the magnetometer of thedetector 72.

As a result, the magnetometer automatically launches, i.e. without theintervention of the operator, the computer program loaded on theprocessing module 59 to guide to the operator in his or her operations.

If the box is telescopic, the operator then adjusts the position, alongthe X axis, of the female portion with respect to the male portion 12 a,according to the image acquisition apparatus 19 and its settings.

The scale arranged on the male portion 12 a of the support and bearing amark for each type of image acquisition apparatus facilitates theadjustment.

Preferably, the operator switches on the light source 51 so as toilluminate the teeth and to project the reference frame, in particular alaser grid, on the teeth.

The operator also fastens the dental retractor to the support. In oneembodiment shown, he or she inserts a first of the right and left tabsbehind a first of the right and left hooks, respectively, then slightlybends the dental retractor in order to allow the second tab to beinserted behind the second hook. When the operator releases his or heraction, the dental retractor attempts to return to its initial shape,but this return to the initial shape is hindered by the hooks. Thepressure of the dental retractor on the support thus obtained ensuresthat the dental retractor is held in position behind the hooks.

Preferably, the processing module 59 is configured to control theautomatic acquisition of one or more updated images and analyze them todetect any incorrect positioning of the image acquisition apparatusand/or of the dental retractor and/or poor illumination and/or anunsuitable support length. More preferably, the image acquisitionapparatus immediately informs the operator thereof so that he or shecorrects the detected defects.

A device according to the invention thus makes it possible to provide apredetermined positioning of the image acquisition apparatus withrespect to the spread opening, and therefore facilitates the acquisitionof updated images. It allows high-quality updated images to be obtained,in particular images that are substantially identical in size, framed inthe same way and suitably sharp. The invention therefore facilitates thelater analysis of the updated images.

The patient, who may also be the operator, then places his or her lipsin the channels defined by the rim 34 of the dental retractor. As shownin FIG. 3, the teeth of the patient are then clearly visible. The closedbox advantageously masks the teeth, thereby protecting the patient'sprivacy.

The device is then in a service position and the image acquisitionapparatus 19 views a composite image I_(c) of the type of that shown inFIG. 3. In this figure, the composite image includes a direct imageI_(d) and eight reflected images I_(r) reflected by the various mirrors16 positioned in the chamber 20.

By actuating the trigger of the acquisition apparatus, the operatoracquires the composite image I_(c). Advantageously, he or shesimultaneously acquires, like in the embodiment of FIG. 3, a front view(direct image I_(d)) and a set of oblique views (reflected imagesI_(r)). Of course, the reflected images are inverted with respect toreality. For example, in the reflected image located above the directimage I_(d), the upper arch is shown below the lower arch.

The reflected images may advantageously correspond to acquisitionconditions in which the optical axis of the acquisition apparatus isstrongly inclined with respect to the sagittal plane. Using theacquisition apparatus under these conditions, with direct observation,i.e. without a mirror, would often be difficult for the patient.

The composite image is next transmitted to the processing module 59, bywired or wireless means, for example by Wi-Fi or by Bluetooth®.

Image processing makes it possible in particular, according toconventional processing methods, to isolate the direct image and the oneor more reflected images. In one embodiment, the processing operationalso includes an operation of inverting the reflected images and/or anoperation of correcting perspective effects and/or an operation ofcorrecting colours by means of the colorimetric calibration chart 34.

Analyzing one of the direct and reflected images, preferably the directimage, makes it possible to determine the acquisition conditions of saidimage, preferably according to the teaching of PCT/EP2015/074896,incorporated by reference. The acquisition conditions of the otherimages may advantageously be deduced therefrom, simply by taking thegeometry of the support 12 into account. In particular, the calibrationof the acquisition apparatus is the same for all of the direct andreflected images. Additionally, simple geometric considerations make itpossible to determine the position and the orientation of theacquisition apparatus in space which, in the absence of a mirror, wouldhave allowed the acquisition apparatus to acquire a reflected image.

In one embodiment, the processing module 59, preferably integratedwithin the image acquisition apparatus 19, controls the acquisition ofmultiple composite images under different acquisition conditions, and inparticular with different focal lengths. For example, first, second andthird composite images may be acquired by successively focusing theacquisition apparatus on the incisors, on the premolars and on themolars. Advantageously, each tooth is thus shown clearly in at least oneof the composite images.

In one embodiment, taking multiple successive images under differentacquisition conditions is the result of a single actuation of thetrigger of the image acquisition apparatus. In particular, the imageacquisition apparatus may be configured to take multiple photographs insuccession, with different focal lengths, as a result of a singletrigger action.

Furthermore, the acquisition apparatus preferably acquires an image ofthe teeth of the patient also showing the translucence and colorimetriccalibration charts.

The processing module 59, having knowledge of the real color andtranslucence properties of the calibration charts, then corrects theimage until the representations of said calibration charts in the imagehave these properties.

In order to make the correction accurate, the light source 51 ispreferably adjusted so that, at the time of acquisition of the image,the calibration charts are illuminated under the same conditions as whenmeasuring the real properties. Using a closed box makes it easier tocontrol the illumination.

All of the images acquired by the acquisition apparatus are thusadvantageously comparable, regardless of the lighting environmentoutside the device at the moment of their acquisition.

As is now clearly apparent, the invention significantly facilitates theanalysis of the updated images.

A device according to the first main refinement advantageously makes itpossible to acquire multiple images very quickly, typically in less thana minute, without recourse to a specialist, in particular to a dentistor an orthodontist. The images may in particular be acquired by thepatient him- or herself or by one of his or her kin, using a simplemobile phone, anywhere, and in particular outside of any medical, dentalor orthodontics practice.

In addition, if the geometry of the support, and in particular theorientation and the positioning of a mirror, is known, it is enough todetermine the acquisition conditions of the direct image in order to beable to determine, by way of simple calculation, the acquisitionconditions of the image reflected by this mirror. The implementation ofthe method described in PCT/EP2015/074896 is considerably accelerated asa result.

Lastly, since the acquisition apparatus 19 is immobile with respect tothe teeth, the composite image is advantageously clear and, if thedevice includes a controlled light source, exhibits good contrast.

A device according to the second main refinement makes it possible totrack variation in the properties of the appearance of the teeth. Italso makes it possible for the patient him- or herself to accuratelymeasure these properties at any time, and in particular shortly before aprosthesis is produced, for example. The appearance of the prosthesis isthus particularly close to that of the teeth of the patient.

A device according to the third main refinement facilitates the controlof the illumination during the acquisition of updated images and allowsthe patient's privacy to be protected.

A kit according to the invention substantially facilitates the use of animaging device according to the invention. In particular, it makes itpossible, in one preferred embodiment, to automatically guide the userin his or her operations. The quality of the updated images isadvantageously improved thereby.

Of course, the invention is not restricted to the embodiments describedand shown, which are provided for illustrative purposes only.

In particular, the shape of the box is not limiting.

Furthermore, although this embodiment is not preferred, the fastening ofthe image acquisition apparatus may employ one or more magnets that arefastened to the image acquisition apparatus and one or more metal partsthat are fastened to the support.

The metal parts of the means for fastening the image acquisitionapparatus may also be replaced, at least partially, with magnets thatare arranged so as to attract the magnets fastened to the support.

The mirror is not necessarily planar. It may in particular be configuredto compensate for perspective effects and/or to reflect particularregions of the mouth.

The mirror may be movable with respect to the support, and in particularmay be translatably movable, in particular to make it possible to modifythe distance between the mirror and the retractor opening and/or theacquisition opening.

The mirror may also be rotatably movable, in particular about an axis ofrotation that is perpendicular to the X axis of the dental retractor,two axes being referred to as perpendicular when two planes that areorthogonal to these axes are perpendicular to one another.

Preferably, the image acquisition apparatus includes an app configuredto guide the operator so that he or she correctly positions and orientsthe mirror. In one embodiment, the positioning and/or the orientation ofthe mirror are facilitated by a scale bearing indications relating tovarious acquisition apparatuses. The operator may thus easily positionthe mirror according to the acquisition apparatus used.

In one embodiment, the device includes one or more actuators that aresuitable for adjusting the length of the support and/or the positioningand/or the orientation of the mirror according to setpoints, preferablyaccording to setpoints received from the image acquisition apparatus 19.

In one embodiment, the device also includes one or more sensorsconfigured to measure the length of the support 12 and/or thepositioning and/or the orientation of the mirror, and a transmittercapable of transmitting said measurement to the image acquisitionapparatus. Advantageously, the device may be optimally configured bycontrolling the actuators according to a setpoint, preferably providedby the image acquisition apparatus, said setpoint preferably being basedon the image observed by the image acquisition apparatus and/or by themeasurements taken by the sensors.

In addition, the number of mirrors is not limited and multiple mirrors,preferably all of the mirrors, preferably have one or more of thepreferred features of the mirror 16 described above. In particular, oneor more of the mirrors may be provided with a sensor, with an actuatorand with means for communicating with the image acquisition apparatus,as described above.

1. A method to acquire dental images of a patient with a supportdefining a chamber that is in communication with an outside of saidchamber via a first opening and via a second opening, said methodcomprising the following steps: fixing a mobile phone in front of thesecond opening; positioning said first opening in front of a mouth ofthe patient; acquiring at least one dental image by means of the mobilephone.
 2. The method as claimed in claim 1, comprising a step beforeacquiring at least one dental image, in which a dental retractor isintroduced in the mouth of the patient.
 3. The method as claimed inclaim 2, in which the dental retractor is fixed on the support in frontof the first opening.
 4. The method as claimed in claim 2, in which thedental retractor is formed as an integral part of the support.
 5. Themethod as claimed in claim 1, in which said positioning comprises apositioning of patient's lips on a rim extending around the firstopening.
 6. The method as claimed in claim 1, comprising an automaticguidance of a user to help positioning of the mouth relative to thesupport, and/or specifying a number of images to be acquired.
 7. Themethod as claimed in claim 1, in which the support comprises lateralwall which extends between two end faces defining said first opening andsaid second opening to, the distance between said openings beingconstant.
 8. The method as claimed in claim 1, in which said chamber issubstantially cylindrical.
 9. The method as claimed in claim 1, in whichthe support is rectangular in cross section.
 10. The method as claimedin claim 1, in which the fixing of the mobile phone on the support isperformed by fastening the mobile phone to the support in only onepredetermined position.
 11. The method as claimed in claim 1, in whichat least said acquiring of said at least one dental image is performedby the patient.
 12. The method as claimed in claim 1, in which saidacquiring is performed in less than a minute, without recourse to aspecialist.
 13. A method to acquire dental images of a patient with asupport defining a chamber that is in communication with an outside ofsaid chamber via a first opening and via a second opening, the distancebetween said openings being constant, said method comprising thefollowing steps: fixing a mobile phone in front of the second opening,in one predetermined position, positioning a mouth of the patient infront of the first opening; acquiring, by the patient, at least onedental image by means of the mobile phone.
 14. The method as claimed inclaim 13, in which said positioning comprises positioning of thepatient's lip on a rim of the support.
 15. The method as claimed inclaim 13, comprising a step before acquiring at least one dental image,in which a dental retractor is introduced in the mouth of the patient.16. The method as claimed in claim 15, in which the dental retractor isfixed on the support in front of the first opening.
 17. The method asclaimed in claim 15, in which the dental retractor is formed as anintegral part of the support.
 18. The method as claimed in claim 13, inwhich the patient is automatically guided for said positioning and/or isspecified of a number of images to be acquired.
 19. The method asclaimed in claim 13, in which the support comprises lateral wall whichextends between two end faces.
 20. The method as claimed in claim 19, inwhich the lateral wall is substantially cylindrical. 21-64. (canceled)